A weblog for professionals in electrical, electronic, mechanical and software engineering with content provided by the members of the Long Island Consultant's Network.

November 2013

November 23, 2013

A logo should convey an immediately clear and unambiguous message, right? How obvious can a logo's message be? In some cases, maybe not as obvious as one might expect.

This highly sylized lettering in the image below has been familiar for many decades to people all over the world. You, the reader, have undoubtedly come to know that you're seeing two letters, "GE", and that the letters stand for "General Electric", the maker of whatever product on which this logo is affixed.

However, I can remember seeing this logo as a child and being very puzzled by it. For what seemed like a very long time, I only saw this logo on the front of a household space heater as nothing more than a squiggly line with no discernible interpretation.

Oh, well. We all eventually grow up, right?

Still, there might be a worthwhile lesson here. Please consider the lettering of the sign below for a local delicatessen in this neighborhood:

The intended main word is of course "Crave", but every time I drive past this store front, I see the word "Grave". It's only a matter of someone's artistry, but still ......

November 11, 2013

The writer prepared a BLOG in August 2009 discussing the pros and cons of various means of recovering and reusing the energy normally dissipated as heat in friction brakes in the operation of HYBRID cars. The ULTRACAP was known at that time but was not widely available and range of product was restricted. Well that has changed and the BLOG will reconsider the ULTRACAP potential use. There are also other contributory factors.

Of these contributory factors the nagging problem is that Li-ion batteries in mass production are not following any reasonable learning curve and the cost are staying very high and in fact the writer suspects that there is more than a little connivance in maintaining the high cost for marketing purposes. Particularly in the of the EV, Electric Only, the cost of a 24Kwh battery, is about $700 per Kwh resulting in battery pack of nearly $18,000 and is a major portion of the car cost as delivered.

What Toyota has apparently done with its very successful PRIUS is actually reduce the Li-Ion pack cost and size and works this smaller battery harder to behave almost as a ULTRACAP to provide the electrical acceleration power and provide the load for regenerative braking and in so doing appears to achieve about a 60% recovery of the braking energy normally lost to heat. What is being suggested here is using the ULTRACAP to augment the smaller Li-ion pack to raise the recovery to nearer the 90% level-----a very nice increase. This will very directly improve the MPGe performance---always desirable.

What is proposed here is to operate in parallel; a ULTRACAP pack with the Li-ion battery pack in such a manner that the peak current sources and sinks are handled by the ULTRACAP while the average current requirement will be handled by the Li-ion.

SIZING THE ULTRACAP PACK----

Calculating an ULTRACAP’s energy use the formula (½ xCxV^2) where the energy will be in watt-seconds; C will be in Farads and V will be in volts. It is an interesting point that Ioxus ULTRACAPS have stamped on the case side a Wh (watt-hour) value, as well as the voltage and the capacity. For example a 2.7 V, 3000F has a 3.042 Wh specification. So to estimate how many ULTRACAPS, you first need to calculate how much energy will have to absorb to decelerate from what design speeds and how quickly. BTW the Wh figure on the Ioxus units is based upon total discharge of a fully charges ULTRACAP cell in this case to 2.7V. In actual practice you can operate the ULTRACAP over a (2.7V to 0.9V) range and achieve 90% of the Wh figure printed on the case. The necessary calculations are tedious but straightforward.

CONCLUSION----

It seems like that ULTRACAPS will soon find their way into the acceleration/deceleration system certainly for HYBRID cars and it is the writer’s guess that even now Toyota engineering people are experimenting on how to incorporate into the next generation PRIUS.

November 06, 2013

A complication has surfaced in my efforts evaporate more water out of the ocean and deposit it on land, where it might do some good. My search for good locations for solar-heated evaporator rafts led me to the Gulf of California, a relatively calm body of ocean water located between the Baja California peninsula and the Mexican mainland. During certain seasons, water vapor from the Gulf of CA is pushed up the slopes of the Western Sierra Madre mountains along the entire west coast of the Mexican mainland that connects the United States with Central America. Movement of moist air to higher altitude and lower pressure causes expansion, cooling, and subsequent condensation, and, hopefully, rainfall. This process is called orographic precipitation.

I initially viewed the high-altitude watersheds as passive, obliging surfaces that would funnel the water into rivers that would deliver it to the irrigation canals and ditches on the coastal plains. That is where the legal farming is done. The sloping mountain faces and valleys are suitable for the cultivation of marijuana and opium poppies. Poppies have critical rainfall requirements: rainfall during some stages of growth, and dryness during other phases of growth and harvesting. The drug industry is an integral part of the Mexican economy. The mountains are not just passive water collectors. They are inhabited by determined people who are armed with automatic weapons. Anyone attempting to install solar-heated rafts in the Gulf of CA will have to deal with the whole gamut of legal and illegal industry, criminal activity, and government corruption. Challenging.

I have not yet found another evaporator raft location that might help increase rainfall in the arid southwestern U.S.A. and Mexico. My fundamental principle is that there is too much water in the ocean, and not enough fresh water on land in places where it is needed. Considerable observation, study, modeling, and economic feasibility estimates lie ahead before we need to confront moral, legal, and political issues. So it's the Gulf of California, warts and all, where we do the study of solar-heated evaporator rafts to increase rainfall.